(a) Technical Field
The present disclosure relates generally to a microphone and a method of manufacturing the same, and more particularly, to a microphone having an improved sensitivity and a method of manufacturing the same.
(b) Description of the Related Art
Microphones can be utilized for a wide variety of uses, such as converting a voice into an electrical signal. Recently, microphones have been gradually downsized. To this end, the microectromechanical system (MEMS) technology has developed. A MEMS microphone is advantageous in that it is more resistant to humidity and heat compared to a conventional electret condenser microphone (ECM), and it may be downsized and integrated with a signal processing circuit.
In general, MEMS microphones are divided into two types: a capacitance-type and a piezoelectric-type.
The capacitance-type MEMS microphone includes a fixed electrode and a vibration membrane. When an external sound pressure is applied to the vibration membrane, a capacitance value is changed because the distance between the fixed electrode and the vibration membrane is changed. Sound pressure is measured based on an electrical signal generated at this time.
Meanwhile, the piezoelectric-type MEMS microphone includes only a vibration membrane. When the vibration membrane is deformed by external sound pressure, an electrical signal is generated due to a piezoelectric effect. Sound pressure is measured based on the electrical signal.
Currently, extensive research is being undertaken in order to improve the sensitivity of the capacitance-type MEMS microphone.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the disclosure, and therefore, it may contain information that does not form the related art that is already known to a person of ordinary skill in the art.